Migration master plan
As with all strategically important projects, companies must first obtain an overview and determine the state of the existing telecommunications infrastructure. In addition to the telephone system, this includes the telecommunications periphery mentioned in the previous section. The duration of ongoing maintenance and service contracts also need to be considered. If it has not been done yet, the company should create a plan for the further development of their telecommunications infrastructure. The strategic planning points to immediate and intermediate-term investment. Before the move to VoIP, a fundamental decision has to be made: to either continue to use the present PBX hardware and build a bridge to the new technology, or to alternatively migrate completely to NGNs.
Gateways or interface cards can translate between your ISDN phone system, analog devices, and the new VoIP connections. This allows you to use the devices of your current telecommunications infrastructure mostly unchanged. However, you get the full NGN functionality range only by completely migrating your infrastructure and devices. First, however, your local network (LAN) must meet some basic requirements. All network components should support Quality of Service (QoS) in order to transmit voice packages preferentially and without delay. The option to power your devices via Power over Ethernet (PoE) as well as setting up different virtual networks (VLANs), is also useful and leads to a leaner infrastructure. Naturally, analog and ISDN phones must be replaced by IP phones.